Electronic apparatus and control method for voice recognition on electric power control

ABSTRACT

Disclosed are a display apparatus and a method of controlling the display apparatus. The display apparatus includes: a signal receiver configured to receive a broadcasting signal; a display configured to display an image based on the received broadcasting signal; a sound receiver configured to receive a sound spoken by a user; a first sound recognizer configured to be supplied with power when the display apparatus is in a standby mode, and determine whether the received sound is a reserved word candidate having a high probability of corresponding to a reserved word; a second sound recognizer configured to be supplied with power when the received sound is determined as the reserved word candidate and to determine whether the received sound is the reserved word; and a controller configured to control the preset operation to be performed when the received sound is determined as the reserved word.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from Korean Patent Application No.10-2013-0161138, filed on Dec. 23, 2013 in the Korean IntellectualProperty Office, the disclosure of which is incorporated herein byreference in its entirety.

BACKGROUND

Field

Apparatuses and methods consistent with the exemplary embodiments relateto an electronic apparatus and a control method thereof, and moreparticularly to an electronic apparatus, which receives a user's voiceand operates in accordance with the received sound, and a control methodthereof.

Description of the Related Art

In an electronic apparatus such as a television (TV) or the like displayapparatus a game console, a navigation system for a vehicle, etc.,control based on a user's voice has been growing. For example, afunction of turning on the electronic apparatus in response to a soundspoken by a user in the state that the electronic apparatus is turnedoff (hereinafter, referred to as a ‘standby mode’) may be one of theapplicable examples of controlling the electric apparatus with a user'svoice.

FIG. 1 shows one of the examples where the electronic apparatus relatedto an exemplary embodiment performs an operation in accordance with auser's voice in the standby mode. First, the electronic apparatusreceives a sound in the standby mode (11). The sound received by theelectronic apparatus may be a user's voice, or a different sound fromthe user's voice. In particular, the user's voice includes a command(hereinafter, referred to as a ‘reserved word’) for instructing theelectronic apparatus to perform a preset operation corresponding to thesound. Next, the electronic apparatus recognizes a possible reservedword (12). If the received sound is, in fact, the reserved word (13),the electronic apparatus performs an operation corresponding to thereserved word (14). For example, if the reserved word is a reserved wordfor “power-on,” the electronic apparatus is woken up from the standbymode and is turned on.

However, a sound recognizer 15 needs to be turned on in the standby modeand be ready at any time to receive a sound and for operation, so thatthe electronic apparatus can receive a sound in the standby mode andrecognize the reserved word. The sound recognizer 15 may for example beimplemented as a microprocessor or the like. Therefore, the soundrecognizer 15 unavoidably consumes power in the standby mode in order toremain active and ready for operation. On the other hand, there has beenan increased demand for configuring the electronic apparatus so as toconsume as little electric power as possible in the standby mode.Accordingly, there is a need of minimizing the power consumption of thesound recognizer 15 operating in the standby mode.

Meanwhile, as a result of improvements to the hardware or software ofthe sound recognizer 15, there is a corresponding increase in thereliability of the sound recognizer 15 in recognizing the reserved word13. However, an improvement to the hardware or software of the soundrecognizer 15 causes a corresponding increase in cost of implementingthe improvement. Also, the power consumption is increased as a result ofan increase in performance of the hardware or software of the soundrecognizer 15. Accordingly, the sound recognizer 15 needs to be moreefficiently designed in order to increase the reliability of the soundrecognizer 15, while at the same time, keeping in mind the costs ofpower consumption.

SUMMARY

One or more exemplary embodiments may provide an electronic apparatus,which can operate in response to a user's voice while consuming theminimum amount of power in a standby mode or a power saving mode, and acontrol method thereof.

The power saving mode may be coincident with the standby mode andincludes any mode in which the electronic apparatus consumes less powerthan that of when the electronic apparatus is in a normal mode.Hereinafter, features of an exemplary embodiment with respect to thestandby mode may also be applied to another exemplary embodiment withrespect to the power saving mode.

The electronic apparatus may consume less power where at least onecomponent of the electronic apparatus is turned off and is not suppliedwith power. Alternatively, the electronic apparatus may consume lesspower where at least one component of the electronic apparatus performsfewer operations than those in the normal mode. Alternatively, theelectronic apparatus may consume less power where at least one componentof the electronic apparatus performs an operation at a lower degree thanthat in the normal mode. The component of electronic apparatus may be ahardware component or a software component.

Also, another exemplary embodiment may provide an electronic apparatus,which can recognize a user's voice with a high reliability and performan operation while minimizing costs or power consumption, and a controlmethod thereof.

According to an exemplary embodiment, there is provided a displayapparatus including: a signal receiver configured to receive abroadcasting signal; a display configured to display an image based onthe received broadcasting signal; a sound receiver configured to receivea sound spoken by a user; a first sound recognizer configured to besupplied with electric power when the display apparatus is in a standbymode, and further configured to determine whether the sound received bythe sound receiver in the standby mode is a reserved word candidatehaving a high probability of corresponding to a reserved word forinstructing the display apparatus to perform a preset operation; asecond sound recognizer configured so as not to be supplied withelectric power in the standby mode, and configured to be supplied withthe electric power when the received sound is determined as the reservedword candidate and to determine whether the received sound is thereserved word; and a controller configured to control the presetoperation to be performed when the received sound is determined as thereserved word.

The first sound recognizer may determine whether the received sound isthe reserved word candidate, based on an energy characteristic includinga level of the received sound.

The first sound recognizer may determine whether the received sound isthe reserved word candidate, based on a human sound characteristicincluding at least one from among a zero-crossing rate, a spectralflatness value and a speech presence probability.

The first sound recognizer may determine whether the received sound isthe reserved word candidate, based on a similarity with the reservedword.

The first sound recognizer may determine whether the received sound isthe reserved word candidate, based on at least one selected from amongan energy characteristic, a human sound characteristic and a similaritywith the reserved word in accordance with current conditions.

At least one of the signal receiver and the display corresponding to thedetermined reserved word may be not supplied with electric power in thestandby mode, and be supplied with the electric power when the receivedsound is determined as the reserved word.

The reserved word may include a first reserved word and a secondreserved word, and the first sound recognizer may determine whether thereceived sound is a reserved word candidate corresponding to the firstreserved word in the standby mode, and determine whether the receivedsound is a reserved word candidate corresponding to the second reservedword when the display apparatus is in a normal mode.

A number of commands corresponding to the second reserved word may belarger than a number of commands corresponding to the first reservedword.

According to an exemplary embodiment, there is provided a method ofcontrolling a display apparatus for displaying an image based on areceived broadcasting signal, the method comprising: receiving a soundspoken by a user; with a first sound recognizer, which is supplied withelectric power when the display apparatus is in a standby mode,determining whether the sound received in the standby mode is a reservedword candidate having a high probability of corresponding to a reservedword for instructing the display apparatus to perform a presetoperation; with a second sound recognizer, which is not supplied withelectric power in the standby mode and is supplied with the electricpower when the received sound is determined as the reserved wordcandidate, determining whether the received sound is the reserved word;and performing the preset operation when the received sound isdetermined as the reserved word.

The determining whether the received sound is the reserved wordcandidate may include determining whether the received sound is thereserved word candidate, based on an energy characteristic including alevel of the received sound.

The determining whether the received sound is the reserved wordcandidate may include determining whether the received sound is thereserved word candidate, based on a human sound characteristic includingat least one from among a zero-crossing rate, a spectral flatness value,and a speech presence probability.

The determining whether the received sound is the reserved wordcandidate may include determining whether the received sound is thereserved word candidate, based on a similarity with the reserved word.

The determining whether the received sound is the reserved wordcandidate may include determining whether the received sound is thereserved word candidate, based on at least one selected from among anenergy characteristic, a human sound characteristic, and a similaritywith the reserved word in accordance with current conditions.

The method may further include: supplying no electric power to anoperation performer that performs an operation corresponding to thereserved word in the standby mode, and supplying the electric power tothe operation performer when the received sound is determined as thereserved word.

The reserved word may include a first reserved word and a secondreserved word, and the determining whether the received sound is thereserved word candidate may include: determining whether the receivedsound is a reserved word candidate corresponding to the first reservedword in the standby mode; and determining whether the received sound isa reserved word candidate corresponding to the second reserved word whenthe display apparatus is in a normal mode.

A number of commands corresponding to the second reserved word may belarger than a number of commands corresponding to the first reservedword.

According to an exemplary embodiment, there is provided a displayapparatus including: a signal receiver configured to receive a signal; adisplay that displays an image based on the signal; a sound receiver,configured to detect a sound; a first sound recognizer configured to beprovided with electric power when the display apparatus is in a standbymode.

The first sound recognizer is configured to determine whether the soundreceived by the sound receiver when the display apparatus is in astandby mode is a reserved word candidate having a high probability ofcorresponding to a reserved word for instructing an element of anoperational performer to perform a first preset operation.

There is provided a second sound recognizer configured so as not to beprovided with electric power while the display apparatus is the standbymode, wherein the second sound recognizer is configured to be suppliedwith electric power when the received sound is determined as thereserved word candidate and to determine whether a received sound is thereserved word.

There is provided a controller configured to control a second presetoperation to be performed when the received sound is determined as thereserved word.

According to an exemplary embodiment, there is provided a method ofcontrolling a display apparatus for displaying an image based on areceived broadcasting signal, the method comprising: receiving a soundspoken by a user with a first sound recognizer, the first soundrecognizer not provided with electric power when the display apparatusis in a standby mode. Determining whether the received sound is areserved word candidate having a high probability of similarity to areserved word; instructing an element of an operational performer toperform a first preset operation if the reserved word candidate has ahigh probability of similarity to the reserved word. Receiving the soundwith a second sound recognizer, the second sound recognizer providedwith electric power when the received sound is determined as thereserved word candidate. Determining whether the received sound is thereserved word, and performing a second preset operation when thereceived sound is determined as the reserved word.

According to an exemplary embodiment, there is provided an apparatuscomprising: a signal receiver configured to receive a broadcastingsignal; a sound receiver configured to detect a received sound spoken bya user; a first sound recognizer configured to be supplied with electricpower when the apparatus is in a standby mode, and determine whether thesound received by the sound receiver while in the standby mode is areserved word candidate having a high probability of corresponding to areserved word for instructing the apparatus to perform a presetoperation.

There is provided a second sound recognizer configured so as not to besupplied with electric power in the standby mode, and to be suppliedwith electric power when the received sound is determined as thereserved word candidate and to determine whether the received sound isthe reserved word; and a controller configured to control the presetoperation to be performed when the received sound is determined as thereserved word.

According to an exemplary embodiment, there is provided a method ofcontrolling an apparatus, the method comprising: receiving a soundspoken by a user with a first sound recognizer, the first soundrecognizer not provided with electric power when the apparatus is in astandby mode; determining whether the received sound is a reserved wordcandidate having a high probability of similarity to a reserved word;instructing an element of an operation performer to perform a firstpreset operation if the reserved word candidate has a high probabilityof similarity to the reserved word; receiving the sound with a secondsound recognizer, the second sound recognizer provided with electricpower when the received sound is determined as the reserved wordcandidate; determining whether the received sound is the reserved word;performing a second preset operation when the received sound isdetermined as the reserved word.

According to an exemplary embodiment, there is provided a displayapparatus comprising a signal receiver configured to receive a signal; adisplay that displays an image based on the signal; a sound receiverconfigured to display a sound; a first sound recognizer configured to beprovided with electric power when the display apparatus is in a standbymode, wherein the first sound recognizer is configured to determinewhether the sound received by the sound receiver is a reserved wordcandidate having a high probability of corresponding to a reserved wordfor instructing an element of an operational performer to perform apreset operation.

There is provided a second sound recognizer configured so as not to beprovided with electric power while the display apparatus is the standbymode, wherein the second sound recognizer is configured to be suppliedwith electric power when the received sound is determined as thereserved word candidate and to determine whether a received sound is thereserved word.

If the current operation mode corresponds to a first operation mode, thefirst sound recognizer determines whether the received sound is areserved word candidate corresponding to a first reserved word; whereinif the current operation mode does not correspond to the first operationmode, the display apparatus determines whether the current operationmode corresponds to a second operation mode.

If the current operation mode corresponds to a second operation mode,the first sound recognizer determines whether the received sound is thereserved word candidate corresponding to a second reserved word; whereina number of commands corresponding to the second reserved word may begreater than a number of commands corresponding to the first reservedword; and a controller configured to control the preset operation to beperformed when the received sound is determined as the reserved word.

According to an exemplary embodiment, there is provided a method ofcontrolling a display apparatus, the method comprising: receiving asound spoken by a user with a first sound recognizer, the first soundrecognizer not provided with electric power when the apparatus is in astandby mode. Determining whether the current operation mode correspondsto a first operation mode, and determining whether the received sound isa reserved word candidate corresponding to a first reserved word.Instructing an element of an operation performer to perform a firstpreset operation if the reserved word candidate has a high probabilityof similarity to the first reserved word. Receiving the sound with asecond sound recognizer, the second sound recognizer provided withelectric power when the received sound is determined as the reservedword candidate. Determining whether the current operation mode does notcorrespond to the first operation mode, and further determining whetherthe current operation mode corresponds to a second operation mode.Instructing the first sound recognizer to determine whether the receivedsound is the reserved word candidate corresponding to a second reservedword, and performing a preset operation when the received sound isdetermined as the first or second reserved word.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and/or other aspects will become apparent and more readilyappreciated from the following description of exemplary embodiments,taken in conjunction with the accompanying drawings, in which:

FIG. 1 shows an example where an electronic apparatus related to anexemplary embodiment while in a standby mode performs an operation inresponse to a user's voice;

FIG. 2 is a block diagram of an electronic apparatus according to anexemplary embodiment;

FIG. 3 shows the kind of sounds received by a sound receiver in theelectronic apparatus according to an exemplary embodiment;

FIG. 4 is a flowchart showing the operation of the electronic apparatusaccording to an exemplary embodiment;

FIG. 5 is a block diagram showing the operation of a first soundrecognizer in the electronic apparatus according to an exemplaryembodiment;

FIG. 6 is a flowchart showing another example of the operation of theelectronic apparatus according to an exemplary embodiment;

FIG. 7 is a block diagram of a display apparatus according to anexemplary embodiment;

FIG. 8 shows the operation of the display apparatus according to anexemplary embodiment in the standby mode; and

FIG. 9 is a flowchart showing the operation of the display apparatusaccording to an exemplary embodiment.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Below, exemplary embodiments will be described in detail. FIG. 2 is ablock diagram of an electronic apparatus 2 according to an exemplaryembodiment. As shown in FIG. 2, the electronic apparatus 2 may beimplemented as a display apparatus such as a television (TV), a gameconsole, a navigation system for a vehicle, etc., and may include anydevice which performs an operation by recognizing a sound. Referring toFIG. 2, the electronic apparatus 2 includes a sound receiver 21, a firstsound recognizer 22, a second sound recognizer 23 and an operationperformer 24.

First, the sound receiver 21 receives a sound. The sound receiver 21 maybe implemented as a microphone. The sound received by the sound receiver21 may include a user's voice, and a sound that is not the user's voice.FIG. 3 shows the kind of sounds that may be received by the soundreceiver 21. First, all the sounds 31 received by the sound receiver 21include noise or the like, and a high level sound 32 having acorresponding low cost and power consumption. The high level sound 32may include, for example, an animal and a human sound 33, although thehigh level sound 32 also includes noise. A human sound 34 may furtherinclude a sound 35 having a high probability of corresponding to apreset reserved word (hereinafter, referred to as a ‘reserved wordcandidate’). The reserved word candidate 35 includes a preset reservedword 36. In FIG. 3, the cost and power consumed in the sound recognitionoperation increases moving from left to right along the horizontal axis.

Referring back to FIG. 2, each of the first sound recognizer 22 and thesecond sound recognizer 23 performs sound recognition with respect tothe sound received by the sound receiver 21. The first sound recognizer22 performs sound recognition as a pre-process for the operation of thesecond sound recognizer 23, that is, the first sound recognizer 23performs sound recognition before the second sound recognizer 23(hereinafter, referred to as ‘first sound recognition’). The secondsound recognizer 23 performs sound recognition as a post-process for theoperation of the first sound recognizer 22, that is the second soundrecognizer 23 performs a sound recognition after the first soundrecognition (hereinafter, referred to as ‘second sound recognition’).That is, the first sound recognition of the first sound recognizer 22may comprise a basic or general recognition, and the second soundrecognition of the second sound recognizer 23 may comprise a moredetailed or in-depth recognition. Specifically, the first soundrecognizer 22 determines whether the sound received by the soundreceiver 21 is the reserved word candidate 35 corresponding to thepreset reserved word 36. On the other hand, the second sound recognizer23 determines whether the sound received by the sound receiver 21 is thepreset reserved word 36.

Referring to FIG. 2, the operation performer 24 performs an operationcorresponding to the reserved word 36. The operation performer 24 mayperform one or more various operations corresponding to the use orfunction of the electronic apparatus 2. For example, if the electronicapparatus 2 is the display apparatus such as a TV, the operationperformer 24 may perform operations of processing an image signal anddisplaying an image based on the processed image signal. The operationperformer 24 may be achieved by hardware, software, or a combinationthereof, and may be provided simultaneously.

FIG. 4 is a flowchart showing operations of the electronic apparatus 2according to an exemplary embodiment. At operation S41, the electronicapparatus 2 receives a sound. Next, at operation S42, the electronicapparatus 2 determines whether the received sound in operation S41 is apreset reserved word candidate 35. If it is determined that the receivedsound is not the preset reserved word candidate 35 (“No” of S42), theelectronic apparatus 2 stops the operation. If it is determined that thereceived sound from operation S41 is the preset reserved word candidate35 (“Yes” of S42), at operation S43, the electronic apparatus 2determines whether the received sound is the preset reserved word 36. Ifit is determined that the received sound is not the preset reserved word(“No” of S43), the electronic apparatus 2 stops the operation. If it isdetermined that the received sound is the preset reserved word (“Yes” ofS43), at operation S44 the electronic apparatus 2 performs an operationcorresponding to the determined reserved word 36.

Thus, according to an exemplary embodiment, the recognition of thereceived sound is divided into the first sound recognition as thepre-process, and the second sound recognition as the post-process. Thatis, the first sound recognition operation for the basic and generalrecognition, filters out beforehand a sound having a low probability ofcorresponding to the reserved word 36 from the received sounds, and themore detailed and in-depth second sound recognition operation isperformed with regard to only a sound corresponding to the reserved wordcandidate 35 having a high probability of corresponding to the reservedword. Thus, it is possible to share functionality of the first soundrecognition and the second sound recognition, and it is also possible tohave efficient and optimized design in consideration of eachcharacteristic of the first sound recognition and the second soundrecognition. Further, a sound having a low probability of correspondingto the reserved word 36 is filtered out by determining beforehandwhether it is the reserved word candidate 35 having a higher probabilityof corresponding to the reserved word 36 before determining whether itis the reserved word, thereby improving a recognition success rate withrespect to the reserved word 36. Thus, as compared with a situation inwhich the hardware or software performance of the limited single soundrecognizer is increased in order to improve the reliability of soundrecognition, the electronic apparatus 2 according to an exemplaryembodiment can perform the sound recognition with higher reliability andlower costs.

Referring back to FIG. 2, the first sound recognizer 22 determineswhether the sound received in the sound receiver 21 corresponds to thereserved word candidate 35, based on at least one from among an energycharacteristic, a sound characteristic, and a similarity with a reservedword 36. For example, the first sound recognizer 22 may determine thesound 32 having a high level from all the received sounds 31, based onan energy characteristic of the sound. Also, the first sound recognizer22 may distinguish the animal sound 33 and the human sound 34 from amongall the sounds 31 or the sounds having a high level, based on animal andhuman sound characteristics. Also, the first sound recognizer 22 maydetermine the reserved word candidate 35 from all the sounds 31, thehigh level sound 32, the animal and human sound 33 or the human sound34, based on a similarity with the preset reserved word 36.

The first sound recognizer 22 may detect the energy characteristic orsound characteristic of the corresponding sound by determining sectionsof the received sound. The first sound recognizer 22 may determine theenergy characteristic or sound characteristic of the corresponding soundwith respect to a time or frequency domain of a sound. The first soundrecognizer 22 may detect the energy characteristic of the correspondingsound with respect to a certain energy level condition of the receivedsound. The first sound recognizer 22 may determine the energycharacteristic of the corresponding sound by using a certain level (dB)of the received sound as a critical point. Also, the first soundrecognizer 22 may determine the energy characteristic, based on arelative ratio between the level of the received sound and a level of areference sound. Further, the first sound recognizer 22 may determinethe energy characteristic, based on a maintenance time for thedetermination section of the received sound.

The first sound recognizer 22 may determine an animal or human soundcharacteristic, based on a zero-crossing rate of the received sound. Thefirst sound recognizer 22 may determine the zero-crossing rate of thereceived sound, based on the number of +/− crossing times with respectto an average silent section level. Also, the first sound recognizer 22may determine a characteristic of the received sound, based on agradient of an input signal distribution in the frequency domain, thatis, based on a spectral flatness value. Further, the first soundrecognizer 22 may determine the characteristic of the received sound,based on a probabilistic model about speech/noise, that is, based on aspeech presence probability.

The first sound recognizer 22 may determine whether the received soundis the reserved word candidate 35, based on similarity with a presetreserved word 36. The first sound recognizer 22 may determine thesimilarity with the reserved word corresponding to some commandsselected among a plurality of commands for controlling the electronicapparatus 2. The first sound recognizer 22 may determine the similaritywith the reserved word, based on a classification or a model lighterthan the second sound recognition of the second sound recognizer 23.

The first sound recognizer 22 may determine whether the received soundis the reserved word candidate 35, based on at least one selected fromamong an energy characteristic, a human sound characteristic andsimilarity with the reserved word, in accordance with currentconditions. FIG. 5 is a block diagram showing operations of a firstsound recognizer 22 in the electronic apparatus according to anexemplary embodiment. As shown in FIG. 5, the first sound recognizer 22may determine whether the received sound is the reserved word candidate35, based on only one from among the energy characteristic, the humansound characteristic and the similarity with the reserved word (refer to(a), (b) and (c) of FIG. 5). Also, the first sound recognizer 22 maydetermine whether the received sound is the reserved word candidate 35,based on sequential combination between two selected from among theenergy characteristic, the human sound characteristic and the similaritywith the reserved word 36 (refer to (d), (e) and (f) of FIG. 5).Further, the first sound recognizer 22 may determine whether thereceived sound is the reserved word candidate 35, based on sequentialcombination of all of the energy characteristic, the human soundcharacteristic and the similarity with the reserved word (refer to (g)of FIG. 5).

In the case of the energy characteristic, computational complexity of analgorithm is low, but reliability is also relatively low. On the otherhand, in the case of the sound characteristic, the computationalcomplexity of the algorithm and the reliability are higher than those ofthe energy characteristic. In the case of the similarity with thereserved word 36, the computational complexity of the algorithm and thereliability are the highest as compared with those of the energycharacteristic and the sound characteristic, but relatively more poweris consumed. It may be determined which is selected from among theenergy characteristic, the human sound characteristic and the similaritywith the reserved word, in accordance with the state of the electronicapparatus 2, ambient environments, a user's request, etc. by taking therespective conditions of the energy characteristic, the human soundcharacteristic and the similarity with the reserved word into account.FIG. 6 is a flowchart showing another example of operations of theelectronic apparatus according to an exemplary embodiment. At operationS61, the electronic apparatus 2 determines the current conditions. Atoperation S62, in accordance with the determined current conditions, theelectronic apparatus 2 may select at least one corresponding to thecurrent condition, from among the energy characteristic, the human soundcharacteristic and the similarity with the reserved word 36. Theelectronic apparatus 2 collects information showing the currentcondition from at least one sensor, for example, a microphone, a camera,an operation sensor, a pressure sensor, a temperature sensor, or anexternal device, and selects at least one corresponding to the currentcondition from among the energy characteristic, the human soundcharacteristic and the similarity with the reserved word 36, based onthe collected information. Next, at operation S63, the first soundrecognizer 22 of the electronic apparatus 2 may determine whether thereceived sound is the reserved word candidate 35, based on at least oneselected from among the energy characteristic, the human soundcharacteristic and the similarity with the reserved word 36.

If the electronic apparatus 2 enters the standby mode, the first soundrecognizer 22 is being supplied with electric power at a normal mode,but the second sound recognizer 23 and the operation performer 24 are inthe power saving mode and is not supplied with electric power. The firstsound recognizer 22 normally operates in the standby mode, anddetermines whether the received sound is the reserved word candidate 35.The second sound recognizer 23 is in the power saving mode, and is thenswitched from the power saving mode into the normal mode to be suppliedwith the electric power if the first sound recognizer 22 determines thatthe received sound is the reserved word candidate 35, thereby performingthe second sound recognition operation. Alternatively, the second soundrecognizer 23 may be in the power saving mode to be supplied with theelectric power but consume less power than a predetermined level.

Therefore, if the electronic apparatus 2 is in the standby mode, thesecond sound recognizer 23 is in the power saving mode while the firstsound recognizer 22 performs the first sound recognition operation,thereby minimizing the power consumption of the electronic apparatus 2even while performing the sound recognition in the standby mode.Meanwhile, the operation performer 24 is woken up from the power savingmode to the normal mode when the second sound recognizer 23 determinesthat the received sound is the reserved word, thereby performing theoperation corresponding to the reserved word. Accordingly, in thestandby mode or the like mode, the electronic apparatus 2 consumes lesspower even while performing the sound recognition operation.

At least one of the first sound recognizer 22 and the second soundrecognizer 23 may be implemented as a hardware component such as anintegrated circuit or a software component such as a computer program.The first sound recognizer 22 and the second sound recognizer 23 may beimplemented in a single body or in separate bodies, respectively. Thesecond sound recognizer 23 may be turned off and not supplied with powerin the power saving mode. Alternatively, the second sound recognizer 23may not operate consuming little power in the power saving mode.Alternatively, the second sound recognizer 23 may perform feweroperations in the power saving mode than those in the normal mode.Alternatively, the second sound recognizer 23 may perform an operationat a lower degree in the power saving mode than that in the normal mode.

According to an exemplary embodiment, the electronic apparatus 2 may beachieved by a display apparatus such as a TV. FIG. 7 is a block diagramof a display apparatus according to an exemplary embodiment. The displayapparatus 7 may include a sound receiver 75, a first sound recognizer76, a second sound recognizer 77, an operation performer 71, an inputreceiver 72, a sub controller 73 and a power supply 74. The soundreceiver 75, the first sound recognizer 76 and the second soundrecognizer 77 shown in FIG. 7 may be configured or function similarly tothe sound receiver 21, the first sound recognizer 22 and the secondsound recognizer 23 described above with reference to FIG. 2. As shownin FIG. 7, the operation performer 71 may include a signal receiver 711,a signal processor 712, a display 713, a sound output 714, a storage715, a communicator 717 and a main controller 716. However, theconfiguration of the display apparatus 7 shown in FIG. 7 is an exemplaryembodiment, and may vary as necessary. That is, although it is notillustrated, the configuration of the display apparatus 7 shown in FIG.7 may exclude at least one of the elements or may include a newadditional element.

The signal receiver 711 receives a signal containing at least one fromamong an image, a sound and a data. The signal receiver 711 includes atuner and receives a signal such as a broadcasting signal. The tuner maybe tuned to one channel selected from among a plurality of channelsunder control of the main controller 716 and receives a signal of thetuned channel. Here, the channel may be selected by a user. The inputreceiver 72 may receive a user's input. The input receiver 72 receives auser's input about the selection of the channel and transmits it to themain controller 716. The input receiver 72 includes a control panelprovided in the display apparatus 7 to receive a user's input, orincludes a remote control signal receiver to receive a remote controlsignal containing a user's input from a remote controller.Alternatively, the input receiver 72 may include an image receiver suchas a camera, and receive an image obtained by photographing a gesture ora similar operation as a user's input. The signal receiver 711 mayalternatively receive a signal from an imaging device such as a set-topbox, a digital versatile disc (DVD) player, etc. or a user terminal suchas a personal computer, etc.

The signal processor 712 performs image processing, sound processing ordata processing with regard to the received signal so that an imageand/or information can be displayed on the display 713 or a sound can beoutput through the sound output 714. For example, the signal processor712 may apply the image processing such as modulation, demodulation,multiplexing, demultiplexing, analog-digital conversion, digital-analogconversion, decoding, encoding, image enhancement, scaling, etc. to thereceived signal.

The display 713 displays the image and/or information based on thesignal processed by the signal processor 712. The display 713 maydisplay an image through various display types such as a liquid crystaldisplay (LCD), a plasma display panel (PDP), an organic light emittingdiode (OLED), etc. The sound output 714 may include a loud speaker, andoutputs a sound based on a signal processed by the signal processor 712.The storage 715 may be achieved by a non-volatile memory such as a flashmemory, a hard disk drive, etc. and stores a program, information anddata needed for operating the display apparatus 7. The communicator 717may communicate with an external device through a wire based or wirelessnetwork, and receive and transmit information and/or data required forthe operation of the display apparatus 7 and communication between thedisplay apparatus 7 to and from the external device. The communicator717 may receive a signal containing an image or the like from a serverthrough Internet or a similar network, or receive a signal containing animage or the like from a peripheral such as a laptop personal computer,a smart phone, a smart pad, etc. through a local wireless network. Thesignal received through the communicator 717 may be processed by thesignal processor 712.

The main controller 716 controls the display apparatus 7 to performoperations in accordance with preset information, or in response to auser's command input through the input receiver 72 or the sound receiver75. For example, the main controller 716 may instruct the signalreceiver 711 and the signal processor 712 to display an image based on asignal of a channel selected and tuned to by a user. The main controller716 may include a control program for performing the instruction,non-volatile and volatile memories in which the whole or part of thecontrol program is stored, and a microprocessor for executing thecontrol program.

The power supply 74 supplies electric power to the sound receiver 75,the first sound recognizer 76, the second sound recognizer 77, the inputreceiver 72, the sub controller and the operation performer 71 in orderto perform the desired operations. The power supply 74 receives an inputalternating current (AC) power and outputs a direct current (DC) powerhaving a predetermined level. To this end, the power supply 74 mayinclude an AC-DC converter, a DC-DC converter, etc.

The sub controller 73 assists the main controller 716 to control thedisplay apparatus 7 to perform the desired operations. For example, inthe standby mode, the operation performer 71 and the second soundrecognizer 77 may be in the power saving mode (or a sleep mode). The subcontroller 73 determines whether the occurrence of an event, whichoccurs during the standby mode, meets a threshold for waking up theoperation performer 71, and in fact wakes up the operation performer 71from the power saving mode to a normal mode, thereby allowing theoperation performer 71 or the like to perform the desired operationcorresponding to the occurred event. The event occurring in the standbymode may be a sound received through the sound receiver 75. Also, theevent occurring in the standby mode may include a user's input receivedthrough the input receiver 72. The sub controller 73 may include anoperation determiner 732 for determining which operation is to beperformed by the operation performer 71 that corresponds to theoccurrence of a particular event. Further, the sub controller 73 mayinclude a power controller 731 that controls the power supply 74 toallow or prevent electric power from being supplied to the operationperformer 71 or the like.

FIG. 8 shows operations of the display apparatus 7 according to anexemplary embodiment in the standby mode. The display apparatus 7 shownin FIG. 8 has a series of stepwise power states 811 to 81 n. That is,the display apparatus 7 may have a ‘power state 1’ 811 of the lowestpower consumption to a ‘power state n’ 81 n of the highest powerconsumption. Meanwhile, the operation performer 73 has an ‘operationperformer 1’ 861 to an ‘operation performer n’ 86 n. The ‘operationperformer 1’ 861 to the ‘operation performer n’ 86 n respectivelycorrespond to the signal receiver 711 or the like included in theoperation performer 73 as shown in FIG. 7. As the ‘operation performer1’ 861 to the ‘operation performer n’ 86 n are sequentially changed fromthe power saving mode to the normal mode, the ‘power state 1’ 811 ischanged in a stepwise fashion to the ‘power state n’ 81 n.

First, in the standby mode, the second sound recognizer 77 of the ‘powerstate 2’ 812 is in the power saving mode. At this time, the soundreceiver 75 receives a sound (82). Then, the first sound recognizer 76determines whether the sound received by the sound receiver 75 is thereserved word candidate (83). The reserved word candidate may correspondto a reserved word 88 for turning on the display apparatus 7, forexample, ‘Hi, TV, turn on’. If the sound received by the sound receiver75 is determined as the reserved word candidate 84 (“Yes” of 84), thepower controller 731 controls the power supply 74 to change the secondsound recognizer 77 from the power saving mode to the normal mode (851).Next, the second sound recognizer 77 determines whether the soundreceived by the sound receiver 75 is the preset reserved word (88). Ifthe sound received by the sound receiver 75 is determined as the presetreserved word (“Yes” of 88), the operation determiner 732 selects the‘operation performer 3’ 863 corresponding to the reserved word (89), andthe power controller 731 controls the power supply 74 so that theselected ‘operation performer 3’ 863 can be woken up from the powersaving mode into the normal mode, thereby performing an operationcorresponding to the reserved word (852). For example, if the reservedword is ‘Hi, TV, turn on’, the sub controller 73 controls the maincontroller 716 or the like to be woken from the power saving mode intothe normal mode, and the main controller 716 or the like performs aninitial operation so that the display apparatus 7 can be ready to beused by a user.

Alternatively, if the reserved word is ‘news briefing,’ the subcontroller 73 controls the signal receiver 711 or the communicator 717,the signal processor 712 and the sound output 714 besides the maincontroller 716 to be woken from the power saving mode to the normalmode. The signal receiver 711 or the communicator 717 may receiveinformation about the new briefing from the broadcasting signal or anexternal server. The signal processor 712 processes the broadcastingsignal or the like to acquire the information about the news briefing,and the sound output 714 may output the information about the newsbriefing. In this case, the display 713 or the like may continuouslykeep the power saving mode. Alternatively, if the reserved word is‘weather briefing,’ in a similar manner to the case of ‘news briefing’the corresponding element of the operation performer 71 is woken fromthe power saving mode to the normal mode, thereby allowing theinformation about the weather briefing to be output. Alternatively, ifthe reserved word is ‘appointed time,’ the information about theappointed time previously set up by a user may be output.

Thus, according to an exemplary embodiment, the display apparatus 7, isconfigured to control a plurality of elements of the operationalperformer 71, based on the reserved word 36, which causes some of theplurality of elements to shift from the power saving mode, to be wokenup and operate in the normal mode, while allowing other elements tocontinuously operate in the power saving mode, thereby avoiding excesspower consumption.

The first sound recognizer 76 of the display 7 may perform the soundrecognition by changing the reserved word candidate 35 in accordancewith current conditions. FIG. 9 is a flowchart showing operations of thedisplay apparatus 7 according to an exemplary embodiment. First, atoperation S91, the display apparatus 7 determines the current operationmode. For example, the operation mode includes the standby mode, thenormal mode, etc. Next, if the current operation mode corresponds to thefirst operation mode (“Yes” of S92), at operation S93 the first soundrecognizer 76 of the display apparatus 7 determines whether the receivedsound is the reserved word candidate corresponding to the first reservedword. For example, if the first operation mode is the standby mode, thefirst sound recognizer 76 determines whether the received sound is thereserved word candidate corresponding to a first reserved word such as‘Hi, TV, turn on.’ If the current operation mode does not correspond tothe first operation (“NO” at S92), at operation S94 the displayapparatus 7 determines whether the current operation mode corresponds tothe second operation mode. If the current operation mode corresponds tothe second operation (“Yes” at S94), at operation S95 the first soundrecognizer 76 determines whether the received sound is the reserved wordcandidate 35 corresponding to the second reserved word 36. For example,if the second operation is the normal mode, the first sound recognizer76 determines whether the received sound is the reserved word candidate35 corresponding to the second reserved word such as ‘channel up,’‘channel down,’ ‘volume up,’ and ‘volume down.’ The number of commandscorresponding to the second reserved word may be greater than the numberof commands corresponding to the first reserved word 36. That is, in thecase of the standby mode or the like, the sound recognition is performedwith regard to only a few first reserved words, and the sound having alow probability of corresponding to the first reserved word is filteredout by the first sound recognizer 76, thereby preventing the secondsound recognizer 77 or operation performer 71 being in the power savingmode from being woken up unnecessarily. Meanwhile, in the case of thenormal mode or the like, the sound recognition is performed with regardto various typically used second reserved words, and the first soundrecognizer 76 recognizes the sound having a high probability ofcorresponding to the second reserved word and smoothly transmits thesound determined as the reserved word candidate 35 to the second soundrecognizer 77.

As described above, according to an exemplary embodiment, the operationsare performed in response to a user's voice operation in the standbymode while minimizing power consumption.

Also, according to an exemplary embodiment, the operations are performedby recognizing a user's voice with higher reliability while minimizingcosts or power consumption.

Although a few exemplary embodiments have been shown and described, itwill be appreciated by those with skill and knowledge in the art thatchanges may be made in these exemplary embodiments without departingfrom the principles and spirit of the invention, the range of which isdefined in the appended claims and their equivalents.

What is claimed is:
 1. A display apparatus comprising: a signal receiverconfigured to receive a broadcasting signal; a display configured todisplay an image based on the received broadcasting signal; a voicereceiver configured to receive a voice spoken by a user; a first voicerecognizer configured to be supplied with electric power when thedisplay apparatus is in a standby mode, and determine, while in thestandby mode, whether a sound characteristic of the received voicecorresponds to a reserved word selected from among a plurality ofreserved words; a second voice recognizer configured so as not to besupplied with electric power in the standby mode, and to be suppliedwith electric power when the sound characteristic of the received voicecorresponds to the selected reserved word, and to determine whether acommand of the received voice is the selected reserved word; and acontroller configured to control the preset operation to be performedwhen the command of the received voice is determined as the selectedreserved word, wherein the reserved word is a predetermined word forinstructing the display apparatus to perform a preset operation, andwherein the reserved word comprises a first reserved word and a secondreserved word, and the first voice recognizer, when the displayapparatus is in the standby mode, determines whether the soundcharacteristic of the received voice corresponds to the first reservedword, and determines whether the sound characteristic of the receivedvoice corresponds to the second reserved word when the display apparatusis in a normal mode.
 2. The display apparatus according to claim 1,wherein the first voice recognizer determines whether the soundcharacteristic of the received voice corresponds to the reserved word,based on an energy characteristic comprising a level of the receivedvoice.
 3. The display apparatus according to claim 1, wherein the firstvoice recognizer determines whether the sound characteristic of thereceived voice corresponds to the reserved word, based on a human soundcharacteristic comprising at least one from among a zero-crossing rate,a spectral flatness value and a speech presence probability.
 4. Thedisplay apparatus according to claim 1, wherein the first voicerecognizer determines whether the sound characteristic of the receivedvoice corresponds to the reserved word, based on a similarity betweenthe received voice and the reserved word, and wherein the second voicerecognizer determines whether the command of the received voice is theselected reserved word, based on the similarity between the receivedvoice and the reserved word.
 5. The display apparatus according to claim1, wherein the first voice recognizer determines whether the soundcharacteristic of the received voice corresponds to the reserved word,based on at least one selected from among an energy characteristic, ahuman sound characteristic and a similarity with the reserved word inaccordance with current conditions.
 6. The display apparatus accordingto claim 1, wherein at least one from among the signal receiver and thedisplay corresponding to the determined reserved word is not suppliedwith electric power in the standby mode, and is supplied with theelectric power when the sound characteristic of the received voice isdetermined to correspond to the reserved word.
 7. The display apparatusaccording to claim 1, wherein a number of commands corresponding to thesecond reserved word is larger than a number of commands correspondingto the first reserved word.
 8. A method of controlling a displayapparatus for displaying an image based on a received broadcastingsignal, the method comprising: receiving a voice spoken by a user with afirst voice recognizer, which is supplied with electric power when thedisplay apparatus is in a standby mode; determining, while in thestandby mode, whether a sound characteristic of the received voicecorresponds to a reserved word selected from among a plurality ofreserved words; with a second voice recognizer, which is not suppliedwith electric power in the standby mode and is supplied with theelectric power when the sound characteristic of the received voicecorresponds to the selected reserved word candidate, determining whethera command of the received voice is the selected reserved word; andperforming the preset operation when the command of the received voiceis determined as the selected reserved word, wherein the reserved wordis a predetermined word for instructing the display apparatus to performa preset operation, and wherein the reserved word further comprises afirst reserved word and a second reserved word, and the determiningwhether the sound characteristic of the received voice corresponds tothe reserved word comprises: determining whether the soundcharacteristic of the received voice corresponds to the first reservedword in the standby mode; and determining whether the soundcharacteristic of the received voice corresponds to the second reservedword when the display apparatus is in a normal mode.
 9. The methodaccording to claim 8, wherein the determining whether the soundcharacteristic of the received voice corresponds to the reserved word isperformed based on an energy characteristic comprising a level of thereceived voice.
 10. The method according to claim 8, wherein thedetermining whether the sound characteristic of the received voicecorresponds to the reserved word is performed based on a human soundcharacteristic comprising at least one from among a zero-crossing rate,a spectral flatness value and a speech presence probability.
 11. Themethod according to claim 8, wherein the determining whether the soundcharacteristic of the received voice corresponds to the reserved word isperformed based on a similarity between the received voice and thereserved word, and wherein the second voice recognizer determineswhether the command of the received voice is the selected reserved word,based on the similarity between the received voice and the reservedword.
 12. The method according to claim 8, wherein the determiningwhether the sound characteristic of the received voice corresponds tothe reserved word is performed based on at least one selected from amongan energy characteristic, a human sound characteristic and a similaritywith the reserved word in accordance with current conditions.
 13. Themethod according to claim 8, further comprising: supplying no electricpower to an operation performer that performs an operation correspondingto the reserved word in the standby mode, and supplying the electricpower to the operation performer when the sound characteristic of thereceived voice corresponds to the reserved word.
 14. The methodaccording to claim 8, wherein a number of commands corresponding to thesecond reserved word is larger than a number of commands correspondingto the first reserved word.
 15. A display apparatus comprising: a signalreceiver configured to receive a signal; a display that displays animage based on the signal; a sound receiver, configured to receive avoice; wherein the display apparatus determines a current operationmode; a first voice recognizer configured to be provided with electricpower when the display apparatus is in a power saving mode, wherein thefirst voice recognizer is configured to determine whether a soundcharacteristic of the received voice corresponds to a reserved wordselected from among a plurality of reserved words; and a second voicerecognizer configured to be supplied with electric power when the soundcharacteristic of the received voice corresponds to the reserved wordand to determine whether the sound characteristic of the received voicecorresponds to the reserved word, wherein if the current operation modecorresponds to a first operation mode, the first voice recognizerdetermines whether the sound characteristic of the received voicecorresponds to a first reserved word, wherein if the current operationmode corresponds to a second operation mode, the first voice recognizerdetermines whether the sound characteristic of the received voicecorresponds to a second reserved word, and wherein a number of commandscorresponding to the second reserved word may be greater than a numberof commands corresponding to the first reserved word; and a controllerconfigured to control the preset operation to be performed when thereceived voice is determined as the first or second reserved word, andwherein the reserved word is a predetermined word for instructing theapparatus to perform a preset operation.